There are many kinds of known arts concerning a resinous impact-energy absorber for absorbing side impact energy. While a door trim has an outside surface with respect to the door trim, the resinous impact-energy absorbers are attached to the outside surface of the door trim. Japanese Unexamined Patent Application Publication No. 8-142234 discloses one type of such a resinous impact-energy absorber, which has a bottom plate and a plurality of ribs. The plurality of ribs extend from the bottom plate and form a lattice shape, and the bottom plate is attached to the outside surface of the door trim. On the other hand, Japanese Unexamined Patent Application Publication No. 2007-55549 discloses a box-type having outer peripheral walls and a top plate integrally provided with the outer peripheral walls. The outer peripheral walls, which extend from the outside surface of the door trim and have a rectangular cylindrical shape, define an opening at the distal end thereof. The opening is closed by a top plate.
However, the former one is, because of the lattice shape, difficult to release from the mold at a time of molding process. Therefore, the height of the rib portions is limited to the extent releasable from the mold (limited to approximately 30 mm). Furthermore, the adjacent rib portions can fall down with leaning against each other, which disturbs buckling of the ribs. Thus, the resinous lattice-shaped impact-energy absorber for absorbing side impact energy cannot stably absorb the impact energy.
On the other hand, the latter one is configured to receive the impact energy on the top plate thereof. However, the larger is the top plate, the lower is the rigidity at the central portion of the top panel (and thus, the size of the top plate is limited to approximately 100 mm in length and 100 mm in width). Furthermore, because the initial load is caused and the impact energy is absorbed only upon the outer peripheral walls making contact with the door trim, the impact energy cannot be absorbed until the outer peripheral walls make contact with the door trim under the impact energy in the event of side impact. Therefore, it is difficult to mount the impact-energy absorber on the door trim without being affected by the concave-convex shape of the door trim.
Therefore, it is a need for the resinous impact-energy absorber that can be mounted to the door trim without being affected by the concave-convex shape of the door trim and, furthermore, can stably absorb the impact energy in the event of side impact.